From the Guidelines
Birt-Hogg-Dubé syndrome should be managed with a multidisciplinary approach, including regular skin examinations, baseline chest imaging, and periodic kidney imaging every 1-2 years to monitor for renal tumors, as recommended by recent guidelines 1.
Key Considerations
- Birt-Hogg-Dubé syndrome is a rare genetic disorder caused by mutations in the FLCN gene, which increases the risk of kidney cancer, among other complications.
- The diagnosis of renal neoplasms associated with Birt-Hogg-Dubé syndrome can be challenging due to regional heterogeneity of tumors, and a standardized approach is recommended 1.
- The term "hybrid oncocytic tumor" should be reserved for hereditary cases, which are often characterized by scattered clusters and individual cells with clear cytoplasm, exhibiting a "checkerboard" mosaic pattern, as seen in BHD syndrome 1.
Management Strategies
- Regular skin examinations and cosmetic treatments like laser therapy or surgical removal may be considered for skin lesions.
- Baseline chest imaging and avoidance of activities that cause sudden changes in air pressure, such as scuba diving or flying in unpressurized aircraft, are recommended for patients with lung cysts.
- Periodic kidney imaging (typically MRI or CT scans every 1-2 years) is crucial to monitor for renal tumors, and a standardized approach to diagnosis and management is essential 1.
Family and Genetic Implications
- Family members should consider genetic testing since Birt-Hogg-Dubé syndrome follows an autosomal dominant inheritance pattern, meaning each child of an affected person has a 50% chance of inheriting the mutation.
- A multidisciplinary approach involving dermatologists, pulmonologists, nephrologists, and genetic counselors is recommended for comprehensive care and to address the various aspects of the syndrome.
From the Research
Birt-Hogg-Dubé Syndrome Overview
- Birt-Hogg-Dubé syndrome is a rare autosomal dominant disorder characterized by diffuse pulmonary cysts, cutaneous fibrofolliculomas or trichodiscomas, and a variety of renal cell cancers 2.
- The syndrome is caused by pathogenic variants in the FLCN gene located on chromosome 17p11.2 2, 3.
Clinical Characteristics
- Patients with Birt-Hogg-Dubé syndrome have an increased risk of developing kidney cancer, which is often bilateral and multifocal 4, 5.
- The risk of developing a renal tumor in this population does not decrease with age and therefore warrants a lifelong screening approach 4.
- Renal cell cancer occurred in 19.1% of patients with Birt-Hogg-Dubé syndrome, and most kidney malignancies occurred after the age of 50 years 5.
Diagnosis and Management
- Diagnosis of Birt-Hogg-Dubé syndrome is based on clinical presentation, genetic test results, and/or a family history of the syndrome 2.
- Patients with Birt-Hogg-Dubé syndrome should undergo chest CT scan to evaluate cystic lesions in the lungs, and routine evaluation of the kidneys for tumor foci using ultrasound, enhanced CT, or MR as appropriate 2.
- Annual abdominal MR examination is recommended for patients with renal tumors <1 cm in diameter, and local excision of renal tumors with preservation of renal function is recommended for tumors >3 cm in diameter 2.
- Routine screenings of kidney cancer during their lifetime are recommended for patients with Birt-Hogg-Dubé syndrome 2, 4.
Screening and Surveillance
- Compliance to renal screening is relatively high, with 83% of patients screened at least annually and 94% at least every two years 6.
- Ultrasound might be a sensitive, cheap, and widely available alternative for MRI or part of the MRIs for detecting clinically relevant renal tumours in BHD patients, but the limitations should be considered carefully 6.
- Abdominal imaging every 36 months is recommended in individuals without renal lesions at initial screening, and interval imaging studies until the largest tumor reaches 3 cm in maximal diameter 4.